edgeofsanity
.020 Over
- Joined
- Jul 13, 2024
- Messages
- 45
- Ride
- 2023 3r
No - '06 zx10r was spot on, my '10 Aprilia v4r was spot on, and my '16 HD sportser is spot on. All checked with GPS. For a 23K (usd) bike, I expected more
Speedometer fix?
- Thread starter TheMunsie
- Start date
-
- Tags
- odometer rocket 3r speedometer
Tal
Living Legend
Haha...tosser!!
Tal
Living Legend
If that is the case, all the 'Your speed' indicators placed on the roadside, especially in built up areas such as towns, must be incorrect.
I have been doing what my speedo says 50 kph when entering a 50kph area and the speed indicator on the roadside tells me im doing considerably less.
I'm certain this is the case in many countries not just here.
This is obvious when on my motorcycle but not in my Car....so i do not think it's nonsense as you suggest.
TURBO200R4
stand up straight and grab the world by the a$$
The ones around here are defective
Just as I pass they flash SLOW DOWN
Just as I pass they flash SLOW DOWN
HarryBo
.060 Over
- Joined
- Dec 13, 2023
- Messages
- 156
- Ride
- '25 Rocket 3R Storm
Oh boy, second try...I mean that it is stupid that manufacturers are making speedometers that are NOT accurate.If that is the case, all the 'Your speed' indicators placed on the roadside, especially in built up areas such as towns, must be incorrect.
I have been doing what my speedo says 50 kph when entering a 50kph area and the speed indicator on the roadside tells me im doing considerably less.
I'm certain this is the case in many countries not just here.
This is obvious when on my motorcycle but not in my Car....so i do not think it's nonsense as you suggest.
Gimlet
Supercharged
Now you mention it, my Harley LRS was spot-on. But it's the only vehicle I've ever had, which I've checked against sat-nav, that was. My cars, vans, pickups have always read 5-10% high and so have all my bikes - except the Harley. All my KTMs have been the furthest out at over 10%.
Personally I don't worry about it. In speed limits I ride or drive to the speedo, not the sat-nav. If they were reading low it would be a different matter.
Einar
.060 Over
- Joined
- Jan 14, 2024
- Messages
- 168
- Location
- Los Estados Unidos
- Ride
- '24 Rocket 3 GT & '23 Tiger 1200 GT Pro
In the United States, there is no regulation regarding accuracy of speedometers. The threat of civil action (lawsuits) ensures that manufacturers strive for speedometers that are very accurate or, to save money and comply with European mandates, read high. This is why American vehicles meant for the U.S. market will typically have very accurate speedometers. I know all of mine have.
In the EU and other European countries, regulations require that speedometers never read below the true speed of the vehicle. For example, the UN/ECE Regulation 39 mandates that speedometers read as follows: 0 ≤ (V1 – V2) ≤ 0.1(V2) + 8 km/h, where V1 is the displayed speed and V2 is the true speed, that the indicated speed is not below the true speed, and that test instrumentation to determine the true speed be accurate to within 0.5%. Test speeds vary based on the vehicle's maximum speed (vMax). For the Rocket 3, with a vMax in the highest category of > 150 km/h, the test speeds are 40, 80, and 120 km/h.
To simplify, this means the as-tested difference between the indicated speed and the true speed must be less than or equal to 10% of the true speed plus 4 km/h, and that the indicated speed be greater than the true speed. But since the test equipment can be up to 0.5% inaccurate, manufacturers need to account for the 0.5% inaccuracy in the speedometer's calibration to ensure they pass. Some examples:
True speed 100 km/h = 0.1(100) + 8 = 14 km/h
Speedometer must read between 100 and 118 km/h.
But since the test equipment can be off from the true speed by 0.5%, the speedometer will be engineered to read somewhere between 100.5 and 117.5 km/h
This is a real-world 0.5% through 17.5% inaccurately high reading.
Using the official test speeds from the regulation:
At 40 km/h, we're looking at a speedometer engineered to read anywhere from 40.2 through 51.8 km/h, or 0.5% through 29.5% high, with 15% being mid-range.
At 80 km/h, we're looking at a speedometer engineered to read anywhere from 80.4 through 95.6 km/h, or 0.5% through 19.5% high, with 10% being mid-range.
At 120 km/h, we're looking at a speedometer engineered to read anywhere from 120.6 through 139.4 km/h, or 0.5% through 16.2% high, with 8% being mid-range.
8% appears to give them a good buffer that complies with the highest test speed, which is right where the Rocket (and most other European vehicles I've owned) sits. Weirdly, my Tiger 1200 GT Pro only reads 3% high.
Correction to earlier, category L3 vehicles (includes the Rocket) are +8 km/h, not +4 km/h. EUR-Lex - 42018X1857 - EN - EUR-Lex
In the EU and other European countries, regulations require that speedometers never read below the true speed of the vehicle. For example, the UN/ECE Regulation 39 mandates that speedometers read as follows: 0 ≤ (V1 – V2) ≤ 0.1(V2) + 8 km/h, where V1 is the displayed speed and V2 is the true speed, that the indicated speed is not below the true speed, and that test instrumentation to determine the true speed be accurate to within 0.5%. Test speeds vary based on the vehicle's maximum speed (vMax). For the Rocket 3, with a vMax in the highest category of > 150 km/h, the test speeds are 40, 80, and 120 km/h.
To simplify, this means the as-tested difference between the indicated speed and the true speed must be less than or equal to 10% of the true speed plus 4 km/h, and that the indicated speed be greater than the true speed. But since the test equipment can be up to 0.5% inaccurate, manufacturers need to account for the 0.5% inaccuracy in the speedometer's calibration to ensure they pass. Some examples:
True speed 100 km/h = 0.1(100) + 8 = 14 km/h
Speedometer must read between 100 and 118 km/h.
But since the test equipment can be off from the true speed by 0.5%, the speedometer will be engineered to read somewhere between 100.5 and 117.5 km/h
This is a real-world 0.5% through 17.5% inaccurately high reading.
Using the official test speeds from the regulation:
At 40 km/h, we're looking at a speedometer engineered to read anywhere from 40.2 through 51.8 km/h, or 0.5% through 29.5% high, with 15% being mid-range.
At 80 km/h, we're looking at a speedometer engineered to read anywhere from 80.4 through 95.6 km/h, or 0.5% through 19.5% high, with 10% being mid-range.
At 120 km/h, we're looking at a speedometer engineered to read anywhere from 120.6 through 139.4 km/h, or 0.5% through 16.2% high, with 8% being mid-range.
8% appears to give them a good buffer that complies with the highest test speed, which is right where the Rocket (and most other European vehicles I've owned) sits. Weirdly, my Tiger 1200 GT Pro only reads 3% high.
Correction to earlier, category L3 vehicles (includes the Rocket) are +8 km/h, not +4 km/h. EUR-Lex - 42018X1857 - EN - EUR-Lex
Last edited:
stingray
Petroleum Consummate
it also gives the odometer reading +8%. Those tires aren't lasting as long as you think.
Similar threads
